global class EmailUtils {
global static void sendEmailWithStandardAttachments(List<String> recipients,String emailSubject,String body,Boolean useHTML,List<Id> attachmentIDs) {
List<Attachment> stdAttachments = [SELECT id, name, body FROM Attachment WHERE Id IN:attachmentIDs];
sendEmailWithStandardAttachments(recipients, emailSubject, body, useHTML, stdAttachments);
}

global static void sendEmailWithStandardAttachments(List<String> recipients,String emailSubject,String body,Boolean useHTML,List<Attachment> stdAttachments) {
List<Messaging.EmailFileAttachment> fileAttachments = new List<Messaging.EmailFileAttachment>();

for(Attachment attachment : stdAttachments) {
Messaging.EmailFileAttachment fileAttachment = new Messaging.EmailFileAttachment();
fileAttachment.setFileName(attachment.Name);
fileAttachment.setBody(attachment.Body);
fileAttachments.add(fileAttachment);
}
sendEmail(recipients, emailSubject, body, useHTML, fileAttachments);
}

global static void sendTextEmail(List<String> recipients,String emailSubject,String textBody) {
sendEmail(recipients, emailSubject, textBody, false, null);
}

global static void sendHTMLEmail(List<String> recipients,String emailSubject,String htmlBody) {
sendEmail(recipients, emailSubject, htmlBody, true, null);
}

global static void sendEmail(List<String> recipients,String emailSubject,String body,Boolean useHTML,List<Messaging.EmailFileAttachment> fileAttachments) {
if(recipients == null) return;
if(recipients.size() == 0) return;
// Create a new single email message object
// that will send out a single email to the addresses in the To, CC & BCC list.
Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage();
//the email is not saved as an activity.
mail.setSaveAsActivity(false);
// Assign the addresses for the To lists to the mail object.
mail.setToAddresses(recipients);
// Specify the subject line for your email address.
mail.setSubject(emailSubject);
// Set to True if you want to BCC yourself on the email.
mail.setBccSender(false);
// The email address of the user executing the Apex Code will be used.
mail.setUseSignature(false);
if (useHTML) {
// Specify the html content of the email.
mail.setHtmlBody(body);
} else {
// Specify the text content of the email.
mail.setPlainTextBody(body);
}
// Specify FileAttachments
if(fileAttachments != null && fileAttachments.size() > 0) {
mail.setFileAttachments(fileAttachments);
}
// Send the email you have created.
Messaging.sendEmail(new Messaging.SingleEmailMessage[] { mail });
}

/**
* null => false
* '' => false
* ' ' => false
* 'x' => false
* 'x@' => false
* 'x@x' => false
* 'x@x.x' => true
*/
global static Boolean isValidEmailAddress(String str){
if(str != null && str.trim() != null && str.trim().length() > 0){
String[] split = str.split('@');
if(split != null && split.size() == 2){
split = split[1].split('\\.');
if(split != null && split.size() >= 2){
return true;
}
}
}
return false;
}

global static Boolean isNotValidEmailAddress(String str){
return !isValidEmailAddress(str);
}

}